The wise parents can tell whether their children are telling the truth____ they listen to their excuses to wrong deeds.

A．the first time

B．for the first time

C．every time

D．for every time

I can't help _____ the cleaning _____ I'm busy mixing up some dumplings now.[ ]

A. doing, because

B. to do, now that

C. doing, since

D. to do, therefore